It is known a disk-clamping device including a turntable for disk mounting, fit on an output rotation shaft of a dedicated motor for driving the disk; a plurality of clamp pawls (chucking pawls), supported rotatably in a direction of clamping the disk on the turntable and of unclamping the disk, through a plurality of windows formed on the turntable; a rotating and elevating member, which is disposed on the backside of the turntable rotatably and in ascendable/descendable manner in synchronization with the turntable, and, when it goes up, causes the clamp pawls to project and rotate through the windows in a direction of clamping the disk, and, when it goes down, causes the clamp pawls to pull in into the windows; a push-up spring urging upward the rotating and elevating member; and a clamp-releasing lever causing the rotating and elevating member to move in a direction of pushing down the member against an urging force of the push-up spring and in a direction of releasing the push down; wherein the clamp-releasing lever is arranged to be interlocked with a pickup (see Patent Documents 1 and 2, for example).
Patent Document 1: JP-A2002-352496 (p. 5 and FIG. 1)
Patent Document 2: Japanese patent No. 3213558 (p. 6 and FIG. 18)
Since the conventional disk-clamping device is arranged as mentioned above, the clamp-releasing lever derives its driving source from a motor for feeding the pickup. Regrettably, the motor for pickup driving has usually low torque. Accordingly, driving the clamp-releasing lever using the motor having low torque in a direction of pulling in the clamp pawls (in a direction of unclamping the disk) against an urging force of the push-up spring of the rotating and elevating member occurs a torque shortage, and therefore, the clamp-releasing lever and the clamp pawls are likely to bring about malfunction. Then, in order for the clamp-releasing lever to smoothly operate with the motor having low torque in a direction of pulling in (unclamping) the clamp pawls, it has only to break an urging force of the push-up spring. However, the push-up spring having a low urging force destabilizes the disk-clamping force of the clamp pawl. Moreover, it is thinkable that the motor having low torque may be replaced with a power motor, but, in this case, it cannot strive for miniatuarization of the reproducing portion.
The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a high reliable disk-clamping device that provides a strong and steady clamping of the disk mounted on the turntable, and offers a secure and smooth stable operation of the clamp-releasing system, with a motor for mode transformation already existing in a disk changer.